Preliminary Study On Right Atrial Function In Patients With Pulmonary Hypertension By Strain By Strain Rate And Strain Imaging

Objective:To explore the right atrial (RA) functional changes in patients with pulmonary hypertension (PH) by strain rate and strain imaging, to evaluate the value of strain rate and strain imaging on RA function and to search new parameters of RA function.Methods:The study included 33 healthy participants (10 men and 23 women, 38.09±13.84 years) as the control group and 61 patients with PH as the case group.The patients with PH were divided into three subgroups by pulmonary arterial systolic pressure (PASP):low-grade PH (LPH, n=22, mean age of 46.20±14.98 years), moderate PH (MPH, n=19, mean age of 44.26±17.40 years) and severe PH (SPH, n=20, mean age of 35.68±12.39 years).The conventional echocardiograpy and strain rate/strain imaging were performed and the following parameters were measured or calculated in the control group and all the patients with PH:1. PASP. 2.RV functional parameters:RV tei index, E'/A', RV end-diastolic volume (RVEDV),RV end-systolic volume (RVESV), RV stroke volume (RVSV), RV ejection fraction (RVEF) and et al. RVEDVI,RVESVI and RVSVI were obtained when the volume parameters were adjusted by body surface area (BSA).3. Traditional RA functional parameters:Maximal RA volume (Vmax), minimal RA volume (Vmin), pre-atrail contraction RA volume (Vpre), RA stroke volume (RASV), RA passive emptying volume (RAPEV), RA passive emptying fraction (RAPEF), RA active emptying volume (RAAEV), RA active emptying fraction (RAAEF), RA systolic force (RASF) and et al. RASVI, RAPEVI, RAAEVI and RASFI were obtained when the corresponding parameters were adjusted by BSA.4. Strain rate and strain parameters of RA function:E-peak strain rate (ESR), A-peak strain rate (ASR), systolic strain rate (SSR) and atrial systolic strain (ASS) of RA lateral wall. All the parameters were compared in the three subgroups of patients with PH with in control group and the parameters of RA function were corrected with PASP and the relational parameters of RV function.Results:1.Comparison of RA parameters among all groups:(1) RA conduit function: RAPEF and ESR were both lower in the three PH subgroups than in control group (P<0.05),but no significant difference in ESR was found among the three PH subgroups (P>0.05). (2) RA booster pump function:All RAAEF, RASFI, ASR and ASS were higher in the three PH subgroups than in control group (P<0.05) Thereinto,both RASFI and ASR changed more sensitively among different groups. (3) RA reservoir function:Both RASVI and SSR were higher in the three PH subgroups than in control group (P<0.05).2.Correlation (1) correlation between parameters of RA function and PASP:RA conduit functional parameters:RAPEF was negatively related to PASP (r=-0.65, P<0.05), while ESR and RAPEVI had no correlation with PASP. RA booster pump functional parameters:When PASP<70mmHg, all RAAEF, RASFI, ASS and ASR were positively related to PASP (P<0.01).ASR and ASS had better correlations (r=0.67,0.74). RA reservoir functional parameters:Both RASVI and SSR were positively related to PASP (P<0.01), and better correlation between SSR and PASP (r=0.75). (2) correlation between functional parameters of RA and RV:All ESR, RAPEF, ASR, RASFI, ASS, RAAEVI and SSR were related to RV tei index (P<0.01).All ESR, RAPEF, ASR, RASFI, ASS, RAAEVI, SSR and RASVI were related to E'/A' (P<0.01),ESR and RAPEF had better correlations (r=0.65,0.70).All ESR, RAPEF, ASR, RASFI, ASS, RAAEVI and SSR were related to RVEF (P<0.01),SSR had better correlation (r=-0.65).Conclusions:1. Along with the ascending of PASP, the parameters of RA volume change sensitively, but they can't differentiate the three kinds of RA function.2.Along with the ascending of PASP, RA conduit function presents fall trend and RA reservoir function ascending trend, while RA booster pump function presents ascending trend only in both LPH and MPH groups, falls from the peak in SPH group.3. RAPEF is the most sensitive parameter of RA conduit function,both ASS and ASR the most sensitive parameters of RA booster pump function and SSR the most sensitive parameter of RA reservoir function.4. Strain rate and strain imaging are more sensitive in evaluating RA booster pump function and reservoir function compared to traditional RA functional parameters.